The U.S. Environmental Protection Agency is proposing a rule that would eliminate derate requirements for diesel exhaust fluid (DEF) on certain diesel-powered equipment. The proposal comes after months of feedback from farmers, ranchers, and truckers, who identified DEF-related performance limitations as one of their biggest concerns. EPA South Central Regional Administrator Scott Mason says the new EPA initiative would replace derate requirements with more typical warning signals, allowing drivers more time to address DEF-related issues.
The proposal is currently in a 45-day public comment period, and EPA officials say they’ll review public feedback before issuing a final rule. Mason says the proposal also includes changes aimed at reducing costs for truckers while keeping current emissions standards in place.
Beyond diesel regulations, the EPA is also continuing work on another issue closely watched by agriculture – the agency’s definition of Waters of the United States (WOTUS). Mason says the definition will use plain language, be easy for farmers to understand, and provide lasting legal clarity.
Engine deratement was first introduced as an engine-failure preventive measure but gradually became mandatory under EPA’s requirements. It became a way to monitor emissions from diesel engines, as the engine speed and power are automatically restricted by the vehicle’s computer when the Diesel Exhaust Fluid level is low or depleted. DEF matters because it breaks down highly toxic exhaust into harmless air before it leaves the vehicle.
